The present invention disclosed herein relates to tumor treatment apparatuses, and more particularly, to a carbon ion generating device and a tumor treatment apparatus using the same.
Examples of the radiation therapies include an X-ray therapy, an electron-beam therapy, and an ion-beam therapy. Among the radiation therapies, the X-ray therapy is in the most widespread use because it can be implemented at the lowest cost using the simplest device. It was discovered in 1950's that a tumor can be treated by accelerating and injecting electrons into the tumor by means of an accelerator. However, the electron-beam therapy was formally used as one of the radiation therapies in 1980's due to the implementation of miniaturized ion accelerators. The X-ray or electron-beam therapy broke hydrogen bonds in cancer cells to destroy the DNA of a cancer, but it involved the adverse effect of severely damaging healthy cells on the propagation path. In order to reduce the damage to healthy cells, the technologies of Intensity-Modulated Radiation Therapy (IMRT), Tomotherapy and Cyber Knife have been developed, but they have failed to completely prevent the above adverse effect.
The ion-beam therapy is esteemed as a treatment method that can reduce the adverse effect in the X-ray or electron-beam therapy. Like electrons, an ion beam must be accelerated to a high velocity in order to penetrate a material. The velocity of an ion beam decreases gradually while the ion beam penetrates a material. However, the ion beam undergoes the most energy loss of ionizing radiation immediately before stopping, which is called Bragg peak, for William Henry Bragg who discovered it in 1903. Thus, when the velocity of ions is accurately controlled, the ion-beam therapy can provide a selective local treatment for malignant tumors.
In view of acceleration energy, hydrogen ions (i.e., protons), which are the lightest among all the ions, have been considered as a material for the ion-beam therapy. However, a carbon-ion therapy has recently been esteemed since it was discovered that carbon ions have better biological effects than protons. For example, it was reported that carbon ions are 2.8 times higher in cancer cell kill rate than protons and are 2.5 times lower in cancer recurrence rate than X-rays or protons.